Sensitizing dyes containing a 2-acylamino-5(4)-thiazolone nucleus



Patented Sept. 15, 1953 SENSITIZIN G DYES CONTAINING A Z-ACYL- A'MIN -5 (4) -THIAZOLONE NU CLEUS Per Afibert, Oslo, Norwa Harrow, England,

y, and Edward B. Knott, assignors to Eastman Kodak Company, Rochester, N. Y., a. corporation of New Jersey No Drawing. Application December 29, 1950, Serial No. 203,525

12 Claims.

This invention relates to merocyanine dyes containing a z-acylamino-fim) -thiazolone nucleus and to a method Ior preparing them.

Merocyanine dyes containing a 2-alkylthioor Z-erelkylthio-fifi)-thiazolone nucleus have previously been described by Cook et a1. See Jo ur. Chem. Soc. (1949), page 1435. These dyes were su gfisted as useful intermediates in the synthe s o pen ci n.

We have now prepared new containing a 2-acylamino-5(4) which are useful as sensitizers silver halide emulsions.

The new merocyanine dyes of can be represented mula:

merocyanine dyes -thiazolone group for photographic our invention wherein R represents an alkyl group, such as methyl, ethyl, nepropyl, isopropyl, nt-butyl, isobutyl, n-amyl, n-octyl, fiehydroxyethyl, ,B-ohloroethyl, fi-acetoxyethyl, etc. groups (especially alkyl groups of the formula C I-Iz c wherein m represents a positive integer of from 1 to 8), R represents the acyl group. of a. carboxylic acid, e. g., acetyl, propionyl, butyry l, isobutyryl, benzoyl, o-, m-, and p-toluoyl, etc, L represents a mefih ne r up (subs i ut d and u su sti u ed, e. g., ;,CH.., CR'mwhere B. represents an alkyl group, such as methyl, ethyl, etc.), n rep-.- resents a positive integer from 1 to 2, d represents a. positive integer from 1 to 3, and Z rep.- resents the non-metallic atoms necessary to comselected from the group consisting of those of the thiazole series (e. g. thiazole, i-methylthiazole, 4ephenylthiazole, 5-.methylthiazole, fr-phenylthiazole, 4,5-dimethylthiazole, 4,5-dipheny1thiazole, 4-(2-thienyl)thiazole, etc.), those of the benzothiazole series (e. g. benzothiazole, 4-chlorobenzothiazole, 5-chlorobenzothiazole, 6-ch lorobenzothiazole, 7-ch1orobenzothiazole, siemethylbenzothiazole, 5:1'I1Qthy1b6IlZQt1'll8Z01B, B-methylbenzothiezole, 5-bromobenzothiazole, 6-.-bromo ben zothiazole, ephenylbenzothiazole, 5ephenylbenzqthiezole, 4-methoxyhenzothiazole, 5emeth xybenzothiazole, G-methoxybenzothiazole, 5- ioclobenzothiazolfl. G-iQiiQbenzothiazole, i-ethoxybenzothiaz ole, -ethoxybenzothiajzole, tetrahye drobenzothiazole, 5,6 e dimethoxybenzothiazole, .6-d yme hyl'enebensothiazoler fiehydmxy n zothiazole, fi-hydroxybenzothiazole. etc.), those by the following general forof the naphthothiazole series (e. g. a-naphthothiazole, fi-naphthothiazole, 5-methoxy-p-naphthothiazole, 5 ethoxy 8 naphthothiazole, 8- methoxy-a-naphthothiazole, 7-methoxy-a-naphthothiazole, etc.), those of the thionaphtheno 'i, 6', 4,5-thiazole series (e. g. 4'-methoxythionaphtheno-7, 6, 4,5-thiazole, etc.), those of the oxazole series (e. g. -methyloxazole, 5-rnethyloxazole, 4-phenyloxazole, 4,5-diphenyloxaz ole, 4 ethyloxazole, 4,5-dimethyloxazole, 5-pheny1oxazole, etc.), those of the benzoxazole series (e. g. benzoxazole, fi-chlorobenzoxez'ole, 5-methy1benzoxazole, 5-phenylbenzoxazo1e, fi met'hylbenzoxazole, 5,6-dimethylhenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, 5-ethoxybenzoxazole, 5-chlorobenzoxazole, S-methOXybenzoxazole, 5-hydroxybenzoxazole, 6 hydroxybenzoxazole, etc.), those of the naphthoxazole sea-naphthoxazole, e-naphthoxazole,

those of the selenazole series (e. g. 4- methylselenazole, 4-phenylselenazo1e, etc.), those of the benzoselenazole series (e. g. benzoselenazole, fi-chlorobenzoselenazole, S-methoxyben'zoselenazole, 5.-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), those of the nephthoselenazole series (e. g. a-naphthoselenazole, 5- naphthoselenazole, etc.), those of the thiazoline series (e. g. thiazoline, 4-methylthiazoline, etc.), those of the 2-quinoline series (e. g. quinoline, 3-methylquinoline, fi-methylquinoline, 7-methylquinoline, 8-methylquinoline, fi-chloroquinoline, 8echloroquinoline, fi-methoxyquinoline 6- ethoxyquinoline, fi-hydroxyquinoline, B-hydroxyquinoline, etc.), those of the 4i-quinoline series (e. g. quinoline, 6-methoxyquinoline, '7-methylquinoline, 8-.methylquino1ine, etc.), those of the l-isoquinoline series (e. g. isoquinoline, 3,4-dihydroisoquinoline, etc.), those of the S -isoquinoline series (e. g. isoquinoline, etc.), those of the eggdialnylindolemne series (e. g. 3,3-dimethy1- ingjolenine, 3,3,5etrimethylindo'lenine, 3,3,7-trimethylindolenine, etc.), those of the pyridine series (e. g. pyridine 5,-methylpyridine, etc.), etc. According to the process of our invention, we

wherein R, L, Z, and n have the values set forth above, Ra represents a hydrogen atom, an alkyl group (9. g. methyl, ethyl, etc.) or the any] group Hz 43-NHR1 EX III.

wherein R1 has the values set forth above and X represents an acid radical, e. g. chloride, bromide, acetate, etc. The condensations are advantageously carried out in the presence of an acidbinding agent, e. g. the trialkylamines, such as triethylamine, tri-n-butylamine, etc., dialkylanilines, such as N,N-dimethyl-, N,N-diethylamlines, etc, heterocyclic tertiary amines, such as pyridine, quinoline, N-alkylpiperidines, etc., alkali metal alcoholates, such as sodium ethylate, etc. The condensations can also be carried out in the presence of an inert diluent, such as methanol, ethanol, n-pr-opanol, isopropanol, n-butanol, diethyl ether, acetone, lA-dioxane.

The merocyanine dyes of Formula I above where d is 1 can be prepared by condensing a cyclammonium quaternary salt selected from those represented by the following general formula:

R-1II(=CHCH) -1= -SR4 wherein R, Z, X1, and n have the values set forth above, and R4 represents an alkyl group, such as methyl, ethyl, etc., or an aryl group, such as phenyl o-, m-, and p-tolyl, etc., with a 2-acy1- amino-5 (4) -thiazo1one acid-addition salt selected from those represented by Formula III above. The condensations can advantageously be carried out in the presence of an acid-binding agent, such as the trialkylamines (e. g. triethylamine, tri-n-butylamine, etc.) dialkylanilines (e. g. N,N- dimethyl-, N,I-ldiethylaniline, etc), heterocyclic tertiary amines (e. g. pyridine, quinoline, N-alkyl-piperidines, etc), alkali metal alcoholates (e. g. sodium methylate, sodium ethylate, etc), etc. The condensations can also be carried out in the presence of an inert diluent, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, diethyl ether, acetone, lA-dioxane, etc.

The following examples will serve to illustrate more fully the manner whereby we practice our invention.

Example 1.-[2-(1-ethyZqmnoline)l [at-acetamin0-5 (4) -thiazolonel dimethinemcrocyanine solution was refluxed for 5 minutes, and the reaction mixture was chilled. The precipitate was collected on a filter and then dissolved in warm benzene. The benzene solution was cooled whereupon the desired dye was obtained as green crystals having a melting point of 233 C. It sensitized a gelatino-silver chloride emulsion to 660 m with a maximum lying between 500 and 600 mu. It sensitized a gelatino-silver bromiodide emulsion to 640 m Example 2.-[4-(1-ethylqu'inoline)l [4-(2-acetamino-5 (4) -thiazolonel dimethinemerocyanine This dye was prepared in the same manner as the dye of Example 1 by replacing the 2-[3-acetanilidovinylquinoline ethiodide by a molecularly equivalent amount of 4-eacetanilidovinylquinoline ethiodide, and by recrystallizing the product dye from ethanol instead of benzene. It was obtained as a dark green powder melting at 226 0.

Example s.-[2- (s-emyzbenzomzozen [4- 2- acetamz'no-5 (4) -thz'aeolone) dimethznemerocyam'ne 1.2 g. of 2-acetamino-5(4)-thiazolone hydro bromide and 2.2 g. of 2-pacetanilidovinylbenzoxazole ethiodide were dissolved in a mixture of 5 cc. of ethanol and 1.4 cc. of triethylamine. The solution was refluxed for 5 minutes, and then chilled. The precipitate was collected on a filter and then dissolved in warm chloroform. The chloroform solution was cooled, whereupon the desired dye separated in the form of red needles with a bluish lustre having a melting point of 264 ,0. (turned orange about (3.). It sensitized a gelatino-silver chloride emulsion strongly to 600 m with maxima at 450 and 520 m It sensitized a gelatino-silver bromiodide emulsion to 560 m with a maximum at 530 m Example 4. [2-(3-methylthz'azoline)l [4(2- acetamino-5(4) -thiazolone) l dimcthz'nemerocyam'ne This dye was prepared in the same manner as the dye of Example 1 by replacing the 2-acetanilidovinylquinoline ethiodide with a molecularly equivalent amount of Z-B-acetanilovinylthiazoline methiodide, and by recrystallizing the product dye from pyridine instead of benzene. It was obtained as an orange powder melting at 276 C. It sensitized a gelatino-silver chloride emulsion with a maximum at 590 In and a gelatino-silver bromiodide emulsion with a maximum at 520 my.

5 Emmfle ylbenzothiazolell [4-(2- acetamino 5-(4) -thiaaolone] dtmethinemerocyanine 1.2 g. of Z-acetaminQ-SIG) thiaz'olone hydrobromide and 2.35 g. of'z fl acetanilidovinylbenzothiazole ethiodide were-dissolved in a mixture of 5 pool ethanol and 1,4 cc. of 'triethylamine. The

solution was refluxed 'for 5 minutes and then chilled. The vprecipitate was collected on a filter and then dissolved in a benzene-ethanol mixture. The-solution was cooled, andthe desired dye separated as greenishbrown needles having a "melting point of 228 C. it sensitized a gelatino-silver chloride emulsion to 640 m with maxima at 480 and 550 m -It sensitized a gelatino-silver bromiodideemulsion to 640 my.

Emample l6.-[2-(3-ethylthiaeoline)l [4-(2-acetamino 5(4) thiazolonel -dimethinemerocyanz'ne 1.23. of 2-acetamino- 5f4) thiazolone hydrobromide and 210 "g. "of "z s acetanilidovinylthiazoline ethiodide'weredissolved in'a mixture The solution was refiuxeddor "5 "minutes, and

"thenchilled. "I'heprecipitate was dissolvedina benzene-ethanol solution, and then" cooled. The

tized a gelatino-silver chloride emulsion witha maximum at 500 m Example 7.[2- (3-eth1 Ihenzaelenazole) LM-(Z- acetamino (4) -thiaz0l0ne)\]wdimethinmer0- cyam'ne Se oigcs {O s en-(m d Emmion.

can

-'bromide and 2.5 g. or ii2 -p -acetanilidovinylbenzoselenazole ethiodide were dissolved 1 in a mixture of cc. of ethanol and l.4"cc.*of-"trichloroform. The .chloroform "solution "was "chilled, whereupon the desired d'eseparated as 'glittering, green crystalslhavingn melting. point of 239 C. It "sensitized" both a gelatinovsilver chloride l emulsion-=- and- -a=:.gelatino.-silver I u bromiodide emulsion r with \a hat wlying between 500 and550rm ethylamine. The solution was "refluxed for1 t minutes and then chilled. The prebipitatewas collected on a filter and th'emdissolveddn warm Example 9.--[2-(3-,ethylbenzomazole,)l [4-(2-11- butyramino 5(4) -thiazolonel tetramethinemerocyanine benzoxazole ethiodide,:1):7:.g.sotzfi nebutyramino- "5 4) -thiazolone hydrobromide, cc.. of ethanol, and 0.8 cc. of -triethylamine were 1 refluxed atogether 'for 3 minutes. The reactiommixture was then :cooled and t the precipitate collected .on a filter. The precipitate was dissolved ,in warm methanol, and the solution chilled. ,Thedesired dye was obtained as glossy, dark, purple platelets having a melting pointof 191 C. It sensitized a gelatino-silver, chloride emulsion 'with a-maximumat 630 "m Ewample 10.-[2 (3 ethylbenzozazolell [4-(2- benzamino 5(4)-thiazolone] dimethinemerocyamne This dye was,.,prepared1 in, the same manner as the dye of, ExamDlefB, by, replacinggthe z-acetamino 5 (4) "thiazolone"hydrobromideby a molecularly equivalent amount of z-benzamino- 5(4) -thiazo1one hydrobromidetand lby recrystallizing the product dllQfITOHIyWflIIII ethanol instead of chloroform. It ,was obtained as brick red needles having a melting point:of 262 C. It sensitized a'gelatino s'ilver chloride emulsion with a maximum at 500 m, and a gelatino-silver bromiodide emulsion with .a. maximum, at 530m benzamino -.,5(4) -.fthiazolone )l-dimethinemerocyanine Example 12.-[2-(3-etiiylbeneoxazole)l [4-(2-11- butyramino (4) thiaeoZoneH dimethinemerocyam'ne This dye was prepared in the same manner as the dye of Example 3 by replacing the 2-acetamino 5(4) thiazolone hydrobromide by a molecularly equivalent amount of 2 n butyramino-5(4)-thiazolone hydrobromide, and by recrystallizing the product dye from ethanol instead of chloroform. It was obtained as brick red needles having a melting point of 212 C. It sensitized a gelatino-silver chloride emulsion with a maximum at 510 C. and a gelatino-silver bromiodide emulsion with a maximum at 530 m Example 13.--[2-(3-methylthiazoline)l [4-(2- butyramino 5(4) thiaeolonefl dimethinemerocyanine This dye O=CS $11: This dye was prepared in the same manner as the dye of Example 9 by replacing the 2-(6- acetanilido) -l,3-butadienylbenzoxazole ethiodide by a molecularly equivalent amount of Z-e-acetanilidovinylthiazoline methiodide. The dye was obtained as orange prisms having a melting point of 229 C. It sensitized a gelatino-silver chloride emulsion with a maximum at 500 m The 2-acylamino-5(4) -thiazolone acid addition salts used in the above examples were obtained as follows:

Example 14.2-acetamino-5(4)-thiazolone hydrobromide 8.8 g. of acetylthiohydantoic acid (Wheeler et al.-Amer. Chem. Jour., vol. 46 (1911), Pg. 469) were dissolved in 45 cc. of anhydrous dioxane and 30 cc. of diethyl ether, and 10 cc. of phosphorous tribromide were added. The solution was shaken gently and then stirred manually for several minutes until the whole solidified. The solid was shaken with diethyl ether, and the ether then decanted off. There was obtained a 95 percent yield of the desired intermediate having a melting point of 159 C. It fumed strongly in moist air, but remained stable when stored in a desiccator.

Example 15.-2-benzamino-5(4)-thiaeolone hy- 7.5 g. of N-benzoylthiohydantoic acid (Wheeler et al., 100. cit.) were triturated and then suspended in a mixture of 50 cc. of dioxane and 125 cc. of diethyl ether, and 4 cc. of phophorus tribromide were added. The stoppered flask was shaken mechanically for 30 minutes and then allowed to stand for 3 hours. The thick precipitate which formed was collected on a filter. After washing with diethyl ether, 9.0 g. percent yield) of a cream powder having a melting point of 190 C. (prior darkening) was obtained.

Example 1 6.-2 -n-butyramz'no-5 (4) thiaeolone 'hydrobromide o=os 0 H; d-NH-tL-mm 25.0 g. oi ethyl dithiocarbamate and 36 cc. of n-butyric anhydride were heated together at C. for 4 hours. The reaction product was recrystallized from warm methanol to give yellow needles melting at 45 C. The ethyl N-n-butyryldithiocarbamate thus obtained had the formula:

25.0 g. of the ester obtained above were re fluxed with a solution of 7.5 g. of potassium hydroxide and 10 g. of glycine in 30 cc. of water and 38 cc. of ethanol for 8 hours. The solution was then concentrated and acidified by the method of Wheeler et al., 100. cit. There were thus obtained 16.0 g. of cream needles having a melting point of C. from aqueous ethanol. The N-n-butyrylthiohydantoic acid thus obtained had the formula:

5.1 g. of the N n butyrylthiohydantoic acid obtained above were suspended in a mixture of 25 cc. of dioxane and '75 cc. of diethyl ether, and 4.0 cc. of phosphorus tribromide were added. After shaking the reaction mixture for several minutes, it was allowed to stand. The product obtained was washed with diethyl ether and dried. It was in the form of a colorless powder (94 percent yield) and had a melting point of 220 C. This product was the desired 2-n-butyramino-5 (4) -thiazolone hydrobromide.

By replacing the n-butyric anhydride in the above example by other acid anhydrides, e. g. propionic, isobutyric, 0-, m, and p-toluic, etc. anhydrides, other 2-acy1amino-5(4) -thiazolones can be obtained.

We have found that our new dyes spectrally sensitize photographic silver halide emulsions when incorporated therein. The dyes are especially useful for extending the spectral sensitivity of the customarily employed gelatino-silverchloride, gelatino-silver-chlorobromide, gelatinosilver-bromide and gelatino-silver-bromiodide developing-out emulsions. In the foregoing examples, the extent to which gelatino-silver bromiodide developing-out emulsions can be sensito add the dyes to the emulsions in the form appropriate solvent. Methanol or acetone has proved satisfactory as a solvent for most of our new dyes. Where the dyes throughout the emulsions. The particular solvent used will, of course, depend-on-thesolubility properties of the particular dye.

The concentration of the'dyes in the emulsions be diluted with water, containing from to 100 mg. of dye, is slowly added to about 1000 cc. of gelatino-silver-halide emulsion, with stirring. Stirring is continued until the dye is thoroughly dispersed in the emulsion.

With most of our dyes, from to 20 mg. of dye per liter of gelatino-silver-bromide or bromiodide emulsion (containing about 40 g. of silver halide) suffices to produce the maximum sensitizing eiTect. With the finer grain emulsions. somewhat larger concentration of dye may be needed to produce the maximum sensitizing effeet.

The above statements are only illustrative, as it will be apparent that the dyes can be incorporated in photographic emulsions by any of the other methods customarily employed in the art, e. g. by bathing a plate or film upon which an emulsion is coated in a solution of the dye in an appropriate solvent. However, bathing methods are ordinarily not to be preferred. Emulsions sensitized with the dyes can be coated on suitable supports, such as glass, cellulose derivative film. resin film or paper in the usual manner.

What we claim and desire secured by Letters Patent of the United States is:

1. A merocyanine dye selected from those represented by the following general formula:

N wherein R represents an alkyl group containing from 1 to 8 carbon atoms, R1 represents the acyl group of a carboxylic acid, L represents a methine group, n represents a positive integer from 1 to 2, d represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of 10 1 the thia'zole series, those of the ben'zothiazole series, those of the naphthothiazole series, those of the thiOIiaphtheIlD-Tfi,4,5' thiaZo1e series, those of the oxazole those of the benzoX- the 3 isoquinolin e series, those of the 3,3-di- V 2. The merocyani ne' dye represented by the following formula:

3."Ihe merocyanine dye represented by the following formula:

452115 4. The merocyanine dye represented by the following formula:

s 5. The merocyanine dye represented by the following formula:

6. The merocyanine dye represented by the '7. A method for making merocyanine dyes comprising condensing an acid-addition salt of a 2-acylamino-5(4)-thiazolone selected from tholse represented by the following general formu a:

wherein R1 represents an acyl group of a carboxylic acid an X represents an acid radical with a cyclammonium quaternary salt selected from those represented by the following general formula:

wherein R represents an alkyl group, X1 represents an acid radical, n represents a positive integer of from 1 to 2, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, and D represents a member selected from the group consisting of an alkylmercapto group, an arylmercapto group, a ,8- arylaminovinyl group, and a 6-arylamino-l,3- butadienyl group.

8. A method according to claim '7 for making merocyanine dyes comprising condensing an acidaddition salt of a 2-acylamino-5(4) -thiazo1one with a 2-,B-acetanilidovinylquinoline alkyl salt wherein the alkyl group is an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 8.

9. A method according to claim '7 for making merocyanine dyes comprising condensing an acidaddition salt of a 2-acylamino-5(4)-thiazolone with a 2-(3-acetanilidovinylbenzothiazole alkyl salt wherein the alkyl group is an alkyl group of the formula cmH2m+l wherein m represents a positive integer of from 1 to 8.

10. A method according to claim '7 for making merocyanine dyes comprising condensing an acid-addition salt of a 2-acylamino-5( l)thiazolone with a 2-[3-acetanilidovinylthiazoline alkyl salt wherein the alkyl group is an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 8.

11. A method according to claim '7 for making merocyanine dyes comprising condensing an acid-addition salt of a 2-acylamino-5(4)-thiazolone with a 243-acetanilidovinylbenzoxazole alkyl salt wherein the alkyl group is an alkyl group of the formula CmH2m+1 wherein m is a positive integer of from 1 to 8.

12. A method according to claim '7 for making merocyanine dyes comprising condensing an acidaddition salt of a 2-acylamino-5(4)-thiazolone with a Z-B-acetanilidovinylbenzoselenazole alkyl salt wherein the alkyl group is an alkyl group of the formula CMHZm-i-l wherein m represents a positive integer of from 1 to 8.

PER AfJBERT. EDWARD B. KNOTT.

References Cited in the file of this patent UNITED STATES PATEN'IS Number Name Date 2,078,233 Brooker Apr. 2'7, 1937 2,170,804 Brooker Apr. 2'7, 1937 2,177,402 Brooker Oct. 24, 1939 OTHER REFERENCES 

1. A MEROCYANINE DYE SELECTED FROM THOSE REPSENTED BY THE FOLLOWING GENERAL FORMULA: 